Distributor for automatic stokers



June 4, 1929.

A. M QARTI- IUR DISTRIBUTOR FOR AUTOMATIC STOKERS Filed Oct. 4, 1923 3Sheets-Sheet l jzdarzir 1 June 4, 1929. AMa ARTHUR i 1,716,071,

DISTRIBUTOR FOR AUTOMATIC STOKERS Filed o t. 4, 192:5 s Sheets-sheaf. 2

June 4, 1929. A. M ARTHUR DISTRIBUTOR FOR AUTOMATIC STOKERS Filed Oct.1923 3 Sheets-Sheet ,3

0L 'fgax Patented June 4, 1929.

. unirsosraras ANGUS MACARTHUR, OF CHICAGO, ILLINOIS,

ASSIGNOR TO THE KOPPERS COMPANY,

OF PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

DISTRIBUTOR FOR AUTOMATIC STOKERS.

Application filed October 4, 1923. Seria1.No. 666,554.

The object of this invention is to provide an efficient distributingmeans for maintaining lIl boiler furnaces a well distributed fuel bed,without segregation of the fuel into piles of pieces of uniform sizes,throughout the entire area of the grate. The improved distributing meansof the invention is characterized by being capable of ready installationin boiler furnaces of standard type, for example, boiler furnaces of theautomatic-stoking type which employ a continuousa-nd progressivelymoving grate; and is further characterized by great simplicity andeconomy of construction and installation.

In addition to the general objects recited above, the invention has forfurther objects such other improvements or advantages as may be found toobtain in the structures and devices hereinafter described or claimed.

In the accompanying drawings forming a part of this specification andshowing for purposes of exemplification a preferred form and manner inwhich the invention may be embodied and practiced, but without limitingthe claimed invention specifically to such illustrative instance or.instances:

Figure 1 is a front sectional andelevational View, in part diagrammatic,.of an automatic stok'ing furnace of standard type equipped With theimprovements ofthe invention;'

Fig. 2 is a side elevation of the front portion of such afurnace; and

Fig. '3 is an elevational sectional view taken longitudinally of theline of feed of the fuel into and through the furnace- The samecharacters of reference indicate the same parts in each of the severalviews of the drawings.

In the embodiment illustrated in the drawings, the invention isincorporated in a stand ard type of automatic stoking boiler furnace.For convenience, the persent description will be confined to thisillustrated embodiment of the invention; the novel'features andimprovements made by the invention are susceptible of otherapplications, for example, to furnaces of other types; hence, the scopeof the invention is not confined to the specific use and embodimentherein described as an illustrated example.

The boiler-furnace illustrated in the drawing is provided with thefirebox 11 which ex tends through the front wall 12 of the furnace forreceiving a constant supply of fuel. The continuous grate 13 extendsfrom "side to side of and through the fire box and is mounted at itsfront end beyond the furnace wall 12 on sprocket 14 driven by suitablegearing and power connections 15 for the purpose of advancing the upperreach of the continuous grate constantly into and throughthe fire x.

The fuel is deposited on the grate 13 just in frontof the wall 12zbyagravity feed through a hopper 16 which extends from side to'side of thegrate. An adjustablegate 16 mounted in front of the fire box of thefirebox opening permits regulation of the depthof the fuel bed on thegrate. I i 1 In furnaces .of the type just briefiydescribed, greatdifficulty has been experienced in maintaining proper distribution offuel from side to side of the grate because of the wide extent of suchstructures, and also because of the fact that it is common to employpulverulent or finely divided fuels. Such fuels have a tendency,especially when moist, to agglomerate and to segre gate in piles ofuniform-sized pieces. These conditions of irregularity must be avoided,if that an irregupossible, it being well known lar fuel bed, especiallyin furnacesof the above described type and when finely divided fuels areemployed, is a great detriment to economic distribution of the heatingefiect. Attempts have been madc'to avoid such irregularities butexperience has proved them unsatisfactory in operation and result.Forexample, it has been proposed to feed the fuel into the feed hopper16' from a swingingdischarge chute. This arrangement, however, involvesan expensive driving equil'amentand does very little towards promotingequality in distribution, because of the practical impossibility ofmaintaining a contant volume of flow of the fuel through the chute.

The distributing means of the present in'- vention accomplishes thedesired result of effecting equality in distribution of the fuel on tothe grate and maintains the proper mixture of sizes. of the fuel fromside to side of the grate by an extremely simple expedi ent. Extendingacross and supported by the sides of the upper hopper 17, which may betermed the distributing hopper, is a screw 18 of the ordinaryscrew-conveyer type. The screw 18 receives the fuel directly from thefeed chute 19 and distributes it equally from side to side of the hopper17 with't-he result that complete equal distribution of-the fuel withmixture of the different sized pieces is effected before it falls intothe lower hopper 16 and on to the grate 13. This construction placefromthe center towards the sides, with the result that the amount ofdistribution necessary is reduced. The distributing screw 18 receivesthe fuel directly from the centrally mountedstationary feed chute 19 andfeeds the fuel toward the opposite sides of the hopper.

An intermittent drive is provided for the distributing screw 18. Securedto the constantly rotating shaft 20 of the drive mechanism is a slottedarm 21, in the slot of which projects a stud 22 carried by the lower endof a connecting rod 23. The connecting rod 23 is pivoted at its upperend to an arm 2-l, which arm is in turn pivoted on the axis of rotationof the screw 18. The arm 24 is provided with a pawl 25 which operates aratchet 26 secured to one end of the screw. Vith this construction eachdownward thrust of the connecting rod 23 causes the pawl 25 to effect aone-step movement of the ratchet 26 and screw 18. During the reversemovement of the connecting rod 23 the pawl 25 travels idly over theratchet teeth.

The invention as hereinabove set forth 1 may be variously embodiedwithin the scope of the claims hereinafter made.

I claim:

1. The combination with a continuously movable endless chain grate of areservoir hopper extending across the'entire width of saidgrate andmounted directly over said grate so that saidgrate supports a verticallydescending column of fuel in said hopper as said grate takes up aportionof the fuel while moving across the lower portion of said hopper; aspreader hopper above said reservoir hopper and co-extensive in lengththerewith and communicating throughout its full length, at its lowerportion, with said reservoir hopper at theupper part thereof; adistributing screw arranged in said spreader hopper and provided withboth right and left-hand threads respectively extending in oppositedirections'from a longitudinal central point in said spreader hopper tospread fuel in opposite directions in said spreader hopper from saidcentral point and to discharge fuel from itself throughout its length afuel delivery chute communicating with said spreader hopper at saidcentral point for feeding fuel to said distributing screw; and drivingmechanism for effecting a stepby-step movement of the distributingscrew.

2. The combination with a stoker grate of a reservoir hopper extendingtransversely of the direction of feed by said stoker grate andmounteddirectly over said grate so that said grate supports a reserve column offuel in said hopper as it takes up a portion of the fuel therein whilefeeding transversely across the lower portion of said reservoir hopper;a fuel spreader hopper mounted above said reservoir hopper and'extendinglengthwise thereof and communicating throughoutv its full length withsaid reservoir hopper at the upper part thereof, and arranged to receivefuel from a source of supply; and a powerdriven spreader comprising twosections arranged to move fuel from said source of supply in oppositedirections in said spreader hopper and to discharge fuel from themselvesto said reservoir hopper throughout their length, whereby the deliveryof fuel to the upper portion of said reservoir hopper is constantlyuniform throughout the length thereof and the depth of reserve fuel insaid reservoir hopper is maintained constant throughout its entirelength.

r 3. The combination with a stoker grate of a reservoir hopper extendingtransversely of the direction of feed by said stoker grate and mounteddirectly over said grate so that said grate supports areserve column offuel in said hopper as it takes up a portion of the fuel therein whilefeeding transversely across the lower portion of said reservoir hopper;a fuel spreader hopper mounted above said reservoir hopper and extendinglengthwise thereof and communicating throughout its full length withsaid reservoir hopper at the upper part thereof and arranged to receivefuel from a source of supply; and a driven spreader unit arrangedto'move fuel from said source longitudinally in said spreader hopper andto discharge fuel from itself throughout its length to said reservoirhopper; whereby the delivery of fuel to upper portion of said reservoirhopper is constantly uniform throughout the length thereof and the depthof the reserve fuel in said reservoir hopper is maintained constantthroughout its entire length.

4. The combination with a stoker grate of a reservoir hopper extendingtransversely of the direction of feed by said stoker grate and mounteddirectly over said grate so that said grate supports a reserve column offuel in said hopper as it takes up a portion of the fuel therein whilefeeding transversely across the lower portion of said reservoir hopper;a fuel spreader hopper mounted'above said reservoir hopper andextending'lengthwise thereof and communicating throughout its fulllength with said reservoir hopper at the upper part thereof andunderlying an overhanging fuel delivery chute for said reservoir hopper;and a screw in said spreader hopper for moving fuel from said chutelongitudinally along said spreader hopper and adapted Cir for dischargeof fuel from itself throughout its length downwardly through saidspreader hopper to said reservoir hopper; whereby the delivery of fuelfrom the chute to the upper portion of said reservoir hopper isconstantly uniform throughout the length thereof and the depth of thereserve fuel in said reservoir hopper is maintained constantthroughoutits entire length.

5. The combination with a stoker grate of a reservoir hopper extendingtransversely of the direction of feed by said stoker grate and mounteddirectly over said grate so that said grate supports a reserve column offuel in said hopper as it takes up a portion of the fuel therein whilefeeding transversely across the lower portion of said reservoir hopper;a fuel spreader hopper mounted above said reservoir hopper and extendinglengthwise thereof and communicating throughout its full length withsaid reservoir hopper at the spreaderhopper on opposite sides of saidmeans I for delivering a constant flow of fuel, arranged to spread fuelin opposite directions away from said means and to discharge fuel fromthemselves throughout their. length downwardly through said spreaderhopper to said reservoir hopper; whereby the delivery of fuel from saidmeans to the upper part of said reservoir hopper is constantly uniformthroughout the length thereof and the depth of the reserve fuel in saidreservoir hopper is maintained constant throughout its entire length.

In testimony whereof I have hereunto set my hand.

ANGUS MAOARTHUR.

